1. Technical Field
The present invention relates to a disk drive for driving, for example, a hard disk. More particularly, the present invention relates to a disk drive provided with an actuator for writing and reading data to and from a recording disk.
2. Description of the Related Art
A disk drive, such as a hard disk drive, is used prevalently as a principal data storage means for a computer. The disk drive includes a case called a disk enclosure, and one or more of recording disks for recording data. The recording disk or recording disks are supported for rotation on a spindle fixed to the case, and are driven for rotation by a spindle motor. An actuator for reading and writing data from and to the recording disk is disposed near the recording disk.
The actuator is supported for turning by a bearing on a pivot shaft fixed to the case of the disk drive. The actuator has an arm extending on one side of the pivot shaft, and a magnetic head supported on a free end part of the arm. A coil support extends on the other side of the pivot shaft, and a voice coil included in a voice coil motor (VCM) is mounted on the coil support.
A stator included in the VCM is disposed opposite to the voice coil mounted on the actuator. A magnetic field created between the stator and the VCM is varied to drive the actuator for turning on the pivot shaft. Consequently, the magnetic head mounted on the free end part of the arm of the actuator moves along the surface of the recording disk to access a desired track in the surface of the recording disk for reading or writing data from or to the recording disk.
The recording capacity of the disk drive has progressively increased in recent years, and the enhancement of speed of operations for reading and writing data from and to the recording disk has been required. Although the enhancement of data processing speed, i.e., the data read/write speed of the magnetic head, is naturally important, it is important to enhance the mechanical turning speed of the actuator in making the magnetic head access (seek) a desired track on the recording disk. Thus, it is preferable that the actuator has a small moment of inertia and an intense current is supplied to the voice coil to turn the actuator at a high speed so that the magnetic head is able to access a desired track on the surface of the recording disk quickly.
One prior art technique discloses making an actuator access a desired track on a recording medium controls the operation of the actuator in moving the actuator substantially along a radius of a recording medium by a VCM. This technique makes the actuator access a desired tack on a recording medium, but does not mention any effective technique for preventing the increase of seek time necessary for the actuator to access a desired track.